Five games into a season, trends start to emerge. One thing we never thought we’d say about Michigan’s defense is that we had concerns.

Legitimate concerns.

But Michigan’s elite unit has shown us something that we don’t like. Not once, but twice. And will we see it again?

Twice in five weeks, Michigan’s defense has gotten off to slow starts and it’s been a huge problem each time. In the season opener against Notre Dame, Michigan allowed two long touchdown drives to start the game and fell into a 14-0 hole they couldn’t recover from. Despite fighting back, Michigan lost 24-17.

And then it happened again on Saturday at Northwestern. On the Wildcats’ first three drives, they went touchdown, field goal, touchdown and stole a 17-0 lead. Granted, Michigan’s defense was lock-down from there and the Wolverines came back to win 20-17, but that’s not the point. The point is, the 17-0 hole should never happen in the first place.

Still, the slow starts are reason for concern. It gets exacerbated, of course, that the offense struggled out of the gate, too. But what matters the most is that Michigan’s defense — which we consider to be elite — shouldn’t be allowing these deep holes to dig out of.

“We missed a couple of tackles in the first couple of drives, but I thought we were sound for the rest of the ball game,” Michigan coach Jim Harbaugh said.

What makes the slow starts all the more confusing is that the defense has been downright unstoppable otherwise. They bounced back nicely against Notre Dame, and gave them a chance for a comeback. They completely shut down Northwestern after the 17-point blitz, and made every big play during the final 43 minutes of the game.

It went from ugly to impressive in a hurry.

“It was great,” Harbaugh said. “(Michigan defensive coordinator) Don Brown had some tremendous calls and a couple of them really stood out. We got a free-runner to the quarterback. He’s big, he’s a big guy sitting in the pocket and a really accurate thrower and the receivers were catching balls in tight windows. We’re applying pressure and that helped us. We stopped the running game, too. They played a hell of a ballgame.

“I was really impressed with the guys in the middle, (Bryan) Mone, Lawrence Marshall and Michael Dwumfour. Chase was flying around and hustling all night. Play, after play, after play. Kwity Paye also showed up. As I said, Josh Uche had some speed rushes. He was fast and good. Aidan Hutchinson also got some time as well. I thought the linebackers were running good, making tackles. ”

That’s all good. But with the bigger challenges that lie ahead, slow starts have to disappear. And they have to disappear in a hurry.